In my U.S. Pat. No. 6,025,041 I describe a first generation down feather sheet and wherein the down feathers are retained in a homogeneous form by a chemical binder agent or rigid fibers and further wherein the down feathers are exposed on all sides of the sheet. A primary purpose of that down feather sheet was to provide a sheet of down feathers for use by the apparel fabricating industry as superior insulation in garments. Such a down feather sheet provided a substantially constant distribution of the down feathers and thus prevented the development of cold spots in the insulation. Because the down feathers are exposed in all outer surfaces of the down feather sheet extra care was necessary to prevent the down feathers from detaching from the faces of the sheet or patterns cut from the sheet.
There is a need to develop a down feather sheet for use in many other applications to provide improved thermal insulation, such as in the construction of vehicles where the passenger enclosure which is climatically controlled during hot or cold weather condition needs to be well insulated. Countless other applications exist as one can imagine. However, for such commercial use, as well as in the fabrication of articles of apparel, there is a need to retain the down feathers captive in the sheets or patterns and to make down feather sheet stretchable (elastic) whereby it can be stretched during installation or use when the need arises to do so.
Another problem with down insulating products, such as articles of apparel is that when such articles are washed in a washing machine, the down has a tendency to form clumps and the minute down clusters can come out of the lining fabric. Ideally, such products should be dry cleaned but still the down clusters, being very small and unstable, can be drawn out of the lining fabric. Such affects the insulating quality and the aesthetic appearance of the garment.
More recently, such down feather sheets have been held captive between sheets of non-woven fabrics adhered to opposed top and bottom surfaces of the sheets and held thereto by a glue binder present at the interface with the down sheet. Although, that solution did prevent some escapement of the down feathers, it did not provide for the use of such material in other industrial manufacturing applications as the material, although flexible did not provide for stretching of the sheet to attach it to flexible and rigid shaped objects and in restricted spaces where it is necessary for the sheet to stretch. Also, when used in garments in areas where movement is required such as in underarm areas or knee areas of clothing, rigid down insulating sheets when stretched would tear to form clumps of insulation which would gather in specific areas and become visible to the eye and form cold spots in the garment. Therefore, that improvement did not overcome these existing problems to extend the use of such down feather sheets.